> Source: [sk167460](https://support.checkpoint.com/results/sk/sk167460)

# sk167460 - SSIDs of WLANs running 5 GHz take more time to appear in SMB appliances

| Property | Value |
|----------|-------|
| Solution ID | sk167460 |
| Date Created | 2020-06-15 |
| Last Modified | 2022-07-20 |
| Technical Level | General |
| Products | Spark Firewall (Locally Managed) |
| Versions | R81.10.X |
| Platform | 1500, 1600, 1800 |

## Symptoms

- * SSIDs of WLANs running 5 GHz take more time to appear in SMB appliances (when compared to those running 2.4 GHz).
* The issue occurs in countries using 5 GHz channels that use or overlap with the DFS zone, and is more prominent with the advent of 802.11ac wave 2.   
  **Note**: Dynamic Frequency Selection (DFS) is a WiFi function that enables WLANs to use 5 GHz frequencies that are generally reserved for radars.
* The issue occurs more often with a channel width of 80_80 MHz and 160 MHz on automatic mode. <br />

## Cause

A process called "Channel Availability Check" is executed during the boot process of an Access Point (AP). This process can take between 1 and 10 minutes, depending on which country you live in.  

When wide channels are in use (such as 80_80 MHz and 160 MHz) it takes time for the radio to detect the surrounding radar signals before the radio front-end allows the WiFi module to work. As these wide frequencies utilize the majority of the DFS channel, it is expected that the AP performs a DFS scan on every available frequency to ensure that the configured channel is not interrupted by the DFS radar signal.

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## Solution

This is an expected behavior, no fix is required.  

You can, however, manually set the channel and save the appliance's radio the time to look for the best radar wise channel. As a result, the AP will come up faster.

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